CutaneousCutaneous LarvaLarva MigransMigrans andand MyiasisMyiasis

TerryTerry LL DwelleDwelle MDMD MPHTMMPHTM

1 GeneralGeneral

► CutaneousCutaneous LarvaLarva MigransMigrans (Creeping(Creeping Eruption)Eruption) isis aa cutaneouscutaneous eruptioneruption resultingresulting fromfrom exposureexposure ofof thethe skinskin toto infectiveinfective filariformfilariform larvaelarvae ofof nonnon--humanhuman hookwormshookworms andand StrongyloidesStrongyloides.. ► OccursOccurs inin mostmost warmwarm humidhumid tropicaltropical andand subtropicalsubtropical areasareas ((egeg SouthSouth USAUSA alongalong thethe coasts,coasts, coastscoasts ofof West,West, SouthSouth andand EastEast Africa,Africa, SouthSouth--EastEast Asia,Asia, India,India, Malaysia,Malaysia, SriSri LankaLanka andand ThialandThialand

2 EtiologyEtiology -- CLMCLM

► Hookworms - CLM ƒ Ankylostoma caninum (dog)

ƒ Ankylostoma braziliense (dog, cat) – most common ƒ Urcinaria stenocephala (European dogs) ƒ Bunostoma phlebotomun (cattle) ► Strongyloides – CLM ƒ S pyoncyonis (racoon)

ƒ S myoptami (nutrea) ƒ ? Pelodara ► Gnathostoma spinergium (dog, cat) ► Others ƒ Loa Loa (Calabar swelling)

ƒ Fasciola hepatic (ectopic migration)

3 ClinicalClinical -- CLMCLM

► There is no protective immunity from a prior infection ► Larvae generally wander under the skin for months before they eventually die ► Symptoms start immediately after penetration of the skin ► Generally there is an erythmatous papule at the entry site which often becomes a vesicle ► The larvae generally move a few mm – cm’s per day leaving tunnels that become dry and crusted ► The track can be linear but also twists and turns ► Causes intense pruritus and may become secondarily infected

► Generally there is little flare surrounding the indurated track

► Strongyloides pyocyonis and myoptami clinically present as described. Strongyloides stercoralis causes tracks that are less defined, have a red flare, move more rapidly (10 cm per hour) and persist for only a few hours. This is not called CLM but larva currens.

4 Early

Larva

Late

5 6 TreatmentTreatment DrugDrug AdultAdult dosagedosage PediatricPediatric dosagedosage AlbendazoleAlbendazole 400400 mgmg dailydaily XX 33 400400 mgmg dailydaily XX 33 (drug(drug ofof choice)choice) daysdays daysdays

IvermectinIvermectin (drug(drug 200200 ugug // kgkg dailydaily 200200 ugug // kgkg dailydaily ofof choice)choice) XX 11--22 daysdays XX 11--22 daysdays ThiabendazoleThiabendazole TopicallyTopically TopicallyTopically (alternate)(alternate) (generally(generally dailydaily (generally(generally dailydaily forfor 55 days)days) forfor 55 days)days) Medical Letter, August 2004, Drugs for Parasitic Infections. 7 AdverseAdverse ReactionsReactions Albendazole Occasional: diarrhea, abdominal pain Rare: leukopenia, alopecia, increased serum transaminase levels

Ivermectin Occasional: eczematous skin rash, conjunctivitis Rare: hypotension

Thiabendazole Frequent: Nausea, vomiting, vertigo Occasional: Leudopenia, crystalluria, rash, hallucinations, olfactory disturbance, erythema multiforme, Steven’s Johnson syndrome Rare: Shock, tinnitus, intrahepatic cholestasis, convulsions, angioneurotic edema

8 MyiasisMyiasis

9 MyiasisMyiasis

Family Subfamily Genus and Species Other Names

Calliphoridae Calliphorinae Metallic group

Chrysomyia bezziana Old world screw worm

Callitroga hominivorax New world screw worm

Lucilia spp Green bottles

Calliphora Blue bottles

Non – metallic group

Auchmeromyia luteola Congo floor maggot

Cordylobia anthropophaga Tumbu or mango fly

Sarcophaginae Wohlfahrtia spp Flesh fly

Sarcophaga Flesh fly

Oestridae Dermatobia hominis Human bot fly

Hypoderma spp Larva migrans

Gastrophilus spp Larva migrans

10 GeneralGeneral -- MyiasisMyiasis

►►MyiasisMyiasis isis causedcaused whenwhen flyfly larvaelarvae invadeinvade livingliving tissuestissues oror whenwhen theythey areare harboredharbored inin thethe intestineintestine oror bladderbladder

11 MyiasisMyiasis

►►ThereThere areare 33 categoriescategories ofof myiasismyiasis producingproducing fliesflies ƒƒ ObligatoryObligatory –– LarvaeLarvae mustmust developdevelop inin livingliving tissuestissues ƒƒ FacultativeFacultative –– LarvaeLarvae usuallyusually developdevelop onon carrioncarrion butbut cancan invadeinvade woundswounds ƒƒ AccidentalAccidental –– LarvaeLarvae oror eggseggs areare accidentallyaccidentally ingestedingested andand areare notnot killedkilled inin thethe intestineintestine

12 MyiasisMyiasis

►►MaggotsMaggots maymay attackattack 33 partsparts ofof thethe bodybody ƒƒ CutaneousCutaneous tissuestissues –– invadeinvade sores,sores, wounds,wounds, burrowburrow inin thethe skin,skin, sucksuck bloodblood ƒƒ BodyBody cavitiescavities –– nose,nose, mouth,mouth, ears,ears, orbit,orbit, anus,anus, vaginavagina ƒƒ GastrointestinalGastrointestinal lumenlumen –– flyfly eggseggs // larvaelarvae passpass throughthrough thethe stomachstomach andand bowelbowel andand emergeemerge inin thethe stoolstool

13 MyiasisMyiasis –– NoseNose andand EarsEars ƒ Nasal and ear myiasis is caused by Chrysomyia, Oestrus, Rhinoestrus, and Callitroga flies. The flies lay eggs in the the nasal cavity particularly where there is chronic nasal discharge. The larvae burrow into tissues even to the nasal bone within a few hours. Symptoms include tickling, sneezing, pain and nasal obstruction followed by a purrulent fetid odor and discharge. Can lead to local destruction of bone and cartiledge, and even migrate to the brain. Mortality with Callitroga hominivorax is 8%. Treatment is with a few drops of 15% chloroform in light vegetable oil which causes them to emerge where they can be removed. Control – large scale release of male flies sterilized by gamma radiation.

14 MyiasisMyiasis -- EyeEye

ƒƒ EyeEye myiasismyiasis oror ophthalmomyiasisophthalmomyiasis maymay bebe externalexternal causedcaused byby OestrusOestrus andand WohlfahrtiaWohlfahrtia sppspp causingcausing conjunctivitisconjunctivitis only.only. ƒƒ InternalInternal ophthalmomyiasisophthalmomyiasis isis causedcaused byby DermatobiaDermatobia ,, OestrusOestrus,, GasterophilusGasterophilus andand HypodermaHypoderma.. OestrusOestrus mainlymainly causescauses conjunctivitis.conjunctivitis. TheThe femalefemale flyfly strikesstrikes thethe eyeeye andand instantaneouslyinstantaneously depositsdeposits eggs.eggs. LarvaeLarvae developdevelop whichwhich causecause conjuntivitisconjuntivitis oror invadeinvade thethe eyeeye andand cancan bebe incrediblyincredibly destructive.destructive.

15 MyiasisMyiasis –– AnusAnus andand VaginaVagina

ƒƒ MyiasisMyiasis ofof thethe AnusAnus andand VaginaVagina isis causedcaused mainlymainly byby WohlfahrtiaWohlfahrtia.. EggsEggs areare laidlaid aroundaround thethe anusanus andand vaginavagina ofof adultsadults andand childrenchildren inin poorpoor hygienichygienic conditionsconditions particularlyparticularly wherewhere therethere isis soilingsoiling oror sores.sores. LargeLarge numbersnumbers ofof maggotsmaggots cancan developdevelop inin aa fewfew hours.hours.

16 MyiasisMyiasis -- WoundWound

ƒƒ WoundWound myiasismyiasis isis causedcaused byby bothboth obligatoryobligatory andand facultativefacultative fliesflies includingincluding CalliphoraCalliphora,, LuciliaLucilia,, PhormiaPhormia,, MuscaMusca,, FanniaFannia,, WohlfahrtiaWohlfahrtia,, ChrysomyiaChrysomyia,, andand CallitrogaCallitroga.. TheThe larvaelarvae ofof thesethese fliesflies livelive inin moistmoist foldsfolds ofof skinskin andand enterenter soressores andand wounds.wounds. InIn somesome instancesinstances thesethese maggotsmaggots areare usedused toto debridedebride woundswounds ofof deaddead materialmaterial wherewhere antibioticsantibiotics andand surgerysurgery areare impractical.impractical.

17 MyiasisMyiasis -- UrogenitalUrogenital

ƒƒ UrogenitalUrogenital MyiasisMyiasis isis rarerare andand causedcaused byby larvaelarvae infectinginfecting thethe vaginavagina oror vulvavulva areaarea penetratingpenetrating thethe urethraurethra andand enteringentering thethe bladder.bladder. MostMost ofof thesethese infectionsinfections areare causedcaused byby PsychodaPsychoda,, MuscaMusca,, CalliphoraCalliphora andand SarcophagaSarcophaga..

18 MyiasisMyiasis -- GastrointestinalGastrointestinal

ƒ Gastrointestinal lumen –Eggs and sometimes larvae are deposited on food and occasionally survive the transit through the stomach. They then develop in the folds of the mucous membranes causing pain, vomiting, diarrhea and occasionally ulcers. This infestation may persist for months. Occasionally larvae may be seen in feces or vomitus. The usual flies associated with intestinal myiasis are Musca, Fannia, Chrysomyia, Calliphora, and Lucilia. Covering of food is preventive. Treatment with purgatives will aid elimination and Ivermectin is occasionally worth a trial.

19 EtiologyEtiology -- MyiasisMyiasis

► CutaneousCutaneous ƒ Blood suckers – Congo Floor Maggot Auchmeromyia luteola ƒ Subcutaneous ► Cordylobia anthropophaga (Africa) – Tumbu, Putsi, Ver Du Cayor fly ► Dermatobia hominis (South America) – Macaque, Berne, El Torsalo, Beefworm, Human Bot fly ƒ Creeping Eruption or Dermal Myiasis – Gastrophilus, Hypoderma, Gnathostoma spinergium

20 AuchmeromyiaAuchmeromyia luteolaluteola –– CongoCongo floorfloor maggotmaggot

► WidelyWidely distributeddistributed inin tropicaltropical AfricaAfrica fromfrom seasea levellevel toto 22502250 mm inin bothboth drydry andand wetwet climatesclimates ► OrangeOrange buffbuff coloredcolored blowflyblowfly ► HumanHuman fecesfeces areare itit’’ss mostmost importantimportant foodfood sourcesource ► TheThe larvalarva generallygenerally feedsfeeds onon sleepingsleeping hosthost ► BiteBite isis painless.painless. NoNo otherother infectionsinfections areare transmittedtransmitted byby itit’’ss bite.bite. ► SleepingSleeping onon aa raisedraised bedbed preventsprevents attacks.attacks. ► SprayingSpraying thethe househouse withwith residualresidual insecticidesinsecticides helphelp eliminateeliminate infestationinfestation

21 CordylobiaCordylobia anthropophagaanthropophaga

► CordylobiaCordylobia anthropophagaanthropophaga inin subsub--saharansaharan AfricaAfrica andand SS SpainSpain ► AlsoAlso calledcalled TumbuTumbu,, PutsiPutsi flyfly oror VerVer dudu cayorcayor ► AA largelarge yellowyellow brownbrown flyfly ► EggsEggs areare laidlaid onon sandysandy groundground contaminatedcontaminated withwith fecesfeces andand urineurine oror washedwashed clothing.clothing. LarvaeLarvae emergeemerge andand invadeinvade subcutaneoussubcutaneous tissuestissues andand developdevelop overover 88--1212 days.days. TheyThey emergeemerge fallfall toto thethe groundground pupatepupate andand hatchhatch asas adultsadults inin 1010--2020 days.days. ► MostMost commonlycommonly involvesinvolves thethe back,back, headhead andand neckneck ► MostMost commoncommon inin childrenchildren

22 CordylobiaCordylobia anthropophagaanthropophaga

► Lesion ƒ Starts as a papule which can be prurritic

ƒ Serous exudate is common ƒ Lymphadenopathy is occasionally seen ƒ Can see fever and malaise ƒ Resembles an abscess ƒ Respiratory spicule is seen but retracts when touched ► Diagnosis ƒ Little pain vs a boil

ƒ Spiracles present ƒ Cover with vaseline, glycerin or oil – diagnostic bubbles ► Treatment ƒ Cover with oil

ƒ Pop out like a pimple

23 CordylobiaCordylobia anthropophagaanthropophaga

►►PreventionPrevention ƒƒ AllAll clothingclothing andand towelstowels shouldshould bebe ironedironed onon bothboth sidessides ƒƒ DripDrip drydry clothingclothing hunghung indoorsindoors withwith thethe windowswindows closedclosed toto preventprevent contactcontact withwith fliesflies

24 DermatobiaDermatobia hominishominis

► Widely distributed in Central and South America ► Attacks a wide range of host including livestock

► Bluish gray fly

► Fly lays eggs on other insects particularly mosquitoes. These eggs hitchhike to the host on these other insect’s bellys. On feeling warmth rapidly hatch and penetrate the skin (5-10 minutes). Larvae develop in 6-12 weeks, drop from the skin to the ground, pupate and hatch as adults. ► Lesion ƒ Develop into a small nodule with a central pore (air hole) ƒ Can be multiple ƒ Inflammed swelling of 2-3 cm ƒ Spiricles can be seen from the air hole ƒ Exudate of seroupurulent fluid and dark feces of the larva ƒ Painful and prurritic ƒ Do not suppurate due to bacteristatic action the gut of the larva

25 DermatobiaDermatobia hominishominis

► Diagnosis ƒ Characteristic spiracles and fecal stained serous exudate

► Treatment ƒ Occasionally can be removed like Cordylobia anthropophaga

ƒ Generally requires surgical removal ƒ Care must be taken not to leave portions of the larvae in the wound ► Complications ƒ Loss of eye

ƒ Fatal cerebral myiasis in children - rare ► Control ƒ Insecticides

ƒ Sterilizing male insects with radiation

26 GastrophilusGastrophilus andand HypodermaHypoderma–– CreepingCreeping EruptionEruption ► CommonCommon parasitesparasites ofof horseshorses ((GastrophilusGastrophilus)) andand cattlecattle ((HypodermaHypoderma ovisovis andand lineatumlineatum)) ► EggsEggs areare depositeddeposited onon hairhair oror grasses.grasses. TheThe larvaelarvae hatchhatch ((egeg 11 weekweek inin HypodermaHypoderma)) andand penetratepenetrate thethe skinskin onon contact.contact. ► LarvaeLarvae dodo notnot developdevelop beyondbeyond thethe instarinstar stagestage ► CauseCause swellingswelling andand aa creepingcreeping eruptioneruption inin thethe lowerlower dermisdermis ► HypodermaHypoderma penetratespenetrates deeperdeeper thanthan GastrophilusGastrophilus andand hashas beenbeen reportedreported toto invadeinvade thethe nervousnervous systemsystem

27 ClinicalClinical FeaturesFeatures

►►TunnelsTunnels ofof GastrophilusGastrophilus mimicmimic CLMCLM ►►PruritusPruritus ►►HypodermaHypoderma produceproduce deeperdeeper swellingsswellings thatthat resembleresemble anan abscessabscess ►►MigrateMigrate forfor considerableconsiderable distancesdistances ►►HypodermaHypoderma ovisovis hashas beenbeen associatedassociated withwith CNSCNS invasioninvasion

28 DiagnosisDiagnosis

►►GastrophilusGastrophilus larvaelarvae cancan bebe identifiedidentified byby puttingputting aa smallsmall amountamount ofof clearclear mineralmineral oiloil overover aa lesion.lesion. TheThe larvaelarvae cancan themthem bebe identifiedidentified byby thethe blackblack transversetransverse bandsbands ofof spinesspines onon thethe body.body.

29 TreatmentTreatment

►►GastrophilusGastrophilus larvaelarvae –– needleneedle ►►HypodermaHypoderma –– cruciformcruciform incisionincision

30 31 Chrysomyia A color atlas of tropical medicine and Dermatobia Hominis Larvae parasitology, 2nd edition, Yearbook Medical Publishers

Auchmeromyia luteola larva (Congo Floor Maggot)

Cordylobia (Tumbu)

Dermatobia Hominis Fly Lucilia or Calliphora

32

A color Atlas of Tropical Medicine and Parasitology, 2nd Edition, Yearbook Medical Publishers, pp 314